diff --git a/Misc/NEWS.d/next/Library/2020-12-22-13-16-43.bpo-25246.GhhCTl.rst b/Misc/NEWS.d/next/Library/2020-12-22-13-16-43.bpo-25246.GhhCTl.rst new file mode 100644 index 00000000000..258bb12ff8b --- /dev/null +++ b/Misc/NEWS.d/next/Library/2020-12-22-13-16-43.bpo-25246.GhhCTl.rst @@ -0,0 +1 @@ +Optimized :meth:`collections.deque.remove`. diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c index 15787506763..90bafb0ea86 100644 --- a/Modules/_collectionsmodule.c +++ b/Modules/_collectionsmodule.c @@ -1128,38 +1128,6 @@ deque_insert(dequeobject *deque, PyObject *const *args, Py_ssize_t nargs) PyDoc_STRVAR(insert_doc, "D.insert(index, object) -- insert object before index"); -static PyObject * -deque_remove(dequeobject *deque, PyObject *value) -{ - Py_ssize_t i, n=Py_SIZE(deque); - - for (i=0 ; ileftblock->data[deque->leftindex]; - int cmp = PyObject_RichCompareBool(item, value, Py_EQ); - - if (Py_SIZE(deque) != n) { - PyErr_SetString(PyExc_IndexError, - "deque mutated during remove()."); - return NULL; - } - if (cmp > 0) { - PyObject *tgt = deque_popleft(deque, NULL); - assert (tgt != NULL); - if (_deque_rotate(deque, i)) - return NULL; - Py_DECREF(tgt); - Py_RETURN_NONE; - } - else if (cmp < 0) { - _deque_rotate(deque, i); - return NULL; - } - _deque_rotate(deque, -1); - } - PyErr_SetString(PyExc_ValueError, "deque.remove(x): x not in deque"); - return NULL; -} - PyDoc_STRVAR(remove_doc, "D.remove(value) -- remove first occurrence of value."); @@ -1227,6 +1195,48 @@ deque_del_item(dequeobject *deque, Py_ssize_t i) return rv; } +static PyObject * +deque_remove(dequeobject *deque, PyObject *value) +{ + PyObject *item; + block *b = deque->leftblock; + Py_ssize_t i, n = Py_SIZE(deque), index = deque->leftindex; + size_t start_state = deque->state; + int cmp, rv; + + for (i = 0 ; i < n; i++) { + item = b->data[index]; + Py_INCREF(item); + cmp = PyObject_RichCompareBool(item, value, Py_EQ); + Py_DECREF(item); + if (cmp < 0) { + return NULL; + } + if (start_state != deque->state) { + PyErr_SetString(PyExc_IndexError, + "deque mutated during iteration"); + return NULL; + } + if (cmp > 0) { + break; + } + index++; + if (index == BLOCKLEN) { + b = b->rightlink; + index = 0; + } + } + if (i == n) { + PyErr_Format(PyExc_ValueError, "%R is not in deque", value); + return NULL; + } + rv = deque_del_item(deque, i); + if (rv == -1) { + return NULL; + } + Py_RETURN_NONE; +} + static int deque_ass_item(dequeobject *deque, Py_ssize_t i, PyObject *v) {